Circulation Topic Review Recent Progress in the Understanding and Management of Postoperative Right Ventricular Outflow Tract Dysfunction in Patients With Congenital Heart Disease

Palliative surgery for conotruncal congenital cardiovascu-lar defects such as tetralogy of Fallot and truncus arteri-osus includes reconstruction of the right ventricular (RV) outflow tract (RVOT). Depending on patient age, anatomy, and other factors, a variety of techniques, prosthetic materi-als, and valves are used to reconstruct the RVOT, but essentially all become dysfunctional over time, with obstruc-tion, pulmonary regurgitation (PR), or both. One of the challenges of managing patients with dysfunction of a surgi-cally reconstructed RVOT has been balancing the risks of ongoing RVOT dysfunction against the risks and benefits of open heart surgery to replace the pulmonary valve. This calculus is complicated by the fact that the replacement valve will have a finite lifespan that is substantially shorter than the life expectancy of the patient, so the “wait-or-intervene” dilemma will recur again and again. In general, the informa-tion used to populate these risk-benefit calculations has been limited and confounded by a variety of factors, so clinicians caring for these patients have often been tasked with making recommendations that are based on inadequate or conflicting data. Moreover, there is such wide and often unexplained variability between patients in how the RV remodels in response to dysfunction of the RVOT that it is difficult to systematize practice and to serve all patients optimally. Given the expanding population of adults with tetralogy of Fallot and other disorders associated with RVOT dysfunction, who constitute a large proportion of adults with significant con-genital heart disease,1 this clinical problem will only continue to grow. In recent years, there have been numerous advances in our understanding of and methods for evaluating the physiolog-ical and clinical sequelae of RVOT dysfunction, as well as in the conceptual and technical aspects of managing such dysfunction and in therapeutic technologies. Although these advances have not resolved the difficulties that clinicians encounter in managing these patients, they have helped clarify and address some of the uncertainty. The purpose of this review is to summarize some of the fundamental dimen-sions of this evolution